In an existing Long Term Evolution (LTE) system, a network device indicates a time-frequency location of a control channel to a terminal device by using broadcast information, and then the terminal device performs control channel detection in the time-frequency location of the control channel. The broadcast information carries two pieces of information used to indicate, respectively, a time-domain location and a frequency-domain location of the control channel. The control channel is a resource used for control information transmission.
So far, a technical solution for indicating a time-frequency location of a control channel to a terminal device by a network device has not been defined for a future 5th generation (5G) new radio (NR) system or a future evolved LTE system. If the technical solution for indicating a time-frequency location of a control channel to a terminal device by a network device in the existing LTE system is still used, in the 5G NR system or the future evolved LTE system, signaling overheads of the two pieces of information used for indicating the time-domain location and the frequency-domain location of the control channel are relatively high because there may be a plurality of schemes for configuring the time-frequency location of the control channel in one subframe. As a result, signaling overheads of the broadcast information are relatively high.
To sum up, a technical solution for indicating a time-frequency location of a control channel to a terminal device by a network device needs to be urgently designed for the future 5G NR system or the future evolved LTE system.